Do not treat lifetimes from parent items as influencing child items
```rust
struct A;
impl Bar<'static> for A {
const STATIC: &str = "";
// ^ no future incompat warning
}
```
has no future incompat warning, because there is no ambiguity. But
```rust
struct C;
impl Bar<'_> for C {
// ^^ this lifeimte
const STATIC: &'static str = {
struct B;
impl Bar<'static> for B {
const STATIC: &str = "";
// causes ^ to emit a future incompat warning
}
""
};
}
```
had one before this PR, because the impl for `B` (which is just a copy of `A`) thought it was influenced by a lifetime on the impl for `C`.
I double checked all other `lifetime_ribs` iterations and all of them do check for `Item` boundaries. This feels very fragile tho, and ~~I think we should do not even be able to see ribs from parent items, but that's a different refactoring that I'd rather not do at the same time as a bugfix~~. EDIT: ah nevermind, this is needed for improving diagnostics like "use of undeclared lifetime" being "can't use generic parameters from outer item" instead.
r? `@compiler-errors`
Remove ScopeDepth
The scope depth was tracked, but never seemed to be used for anything.
Every single place that used `(Scope, ScopeDepth)`, matched it on `(p, _)`.
rustc_resolve: fix instability in lib.rmeta contents
rust-lang/rust@23032f31c9 accidentally introduced some nondeterminism in the ordering of lib.rmeta files, which we caught in our bazel-based builds only recently due to being further behind than normal. In my testing, this fixes the issue.
Avoid wrapping constant allocations in packed structs when not necessary
This way LLVM will set the string merging flag if the alloc is a nul terminated string, reducing binary sizes.
try-job: armhf-gnu
Rollup of 6 pull requests
Successful merges:
- #138720 (Specify a concrete stack size in channel tests)
- #139010 (Improve `xcrun` error handling)
- #139021 (std: get rid of pre-Vista fallback code)
- #139025 (Do not trim paths in MIR validator)
- #139026 (Use `abs_diff` where applicable)
- #139030 (saethlin goes on vacation)
r? `@ghost`
`@rustbot` modify labels: rollup
Remove `kw::Empty` uses from `hir::Lifetime::ident`
`hir::Lifetime::ident` is sometimes set to `kw::Empty` and it's really confusing. This PR stops that. Helps with #137978.
r? `@lcnr`
Do not trim paths in MIR validator
From my inline comment:
```
// The type checker formats a bunch of strings with type names in it, but these strings
// are not always going to be encountered on the error path since the inliner also uses
// the validator, and there are certain kinds of inlining (even for valid code) that
// can cause validation errors (mostly around where clauses and rigid projections).
```
Fixes https://github.com/rust-lang/rust/issues/138979
r? `@jieyouxu`
Improve `xcrun` error handling
The compiler invokes `xcrun` on macOS when linking Apple targets, to find the Xcode SDK which contain all the necessary linker stubs. The error messages that `xcrun` outputs aren't always that great though, so this PR tries to improve that by providing extra context when an error occurs.
Fixes https://github.com/rust-lang/rust/issues/56829.
Fixes https://github.com/rust-lang/rust/issues/84534.
Part of https://github.com/rust-lang/rust/issues/129432.
See also the alternative https://github.com/rust-lang/rust/pull/131433.
Tested on:
- `x86_64-apple-darwin`, MacBook Pro running Mac OS X 10.12.6
- With no tooling installed
- With Xcode 9.2
- With Xcode 9.2 Commandline Tools
- `aarch64-apple-darwin`, MacBook M2 Pro running macOS 14.7.4
- With Xcode 13.4.1
- With Xcode 16.2
- Inside `nix-shell -p xcbuild` (nixpkgs' `xcrun` shim)
- `aarch64-apple-darwin`, VM running macOS 15.3.1
- With no tooling installed
- With Xcode 16.2 Commandline Tools
``@rustbot`` label O-apple
r? compiler
CC ``@BlackHoleFox`` ``@thomcc``
`hir::Lifetime::ident` currently sometimes uses `kw::Empty` for elided
lifetimes and sometimes uses `kw::UnderscoreLifetime`, and the
distinction is used when creating some error suggestions, e.g. in
`Lifetime::suggestion` and `ImplicitLifetimeFinder::visit_ty`. I found
this *really* confusing, and it took me a while to understand what was
going on.
This commit replaces all uses of `kw::Empty` in `hir::Lifetime::ident`
with `kw::UnderscoreLifetime`. It adds a new field
`hir::Lifetime::is_path_anon` that mostly replaces the old
empty/underscore distinction and makes things much clearer.
Some other notable changes:
- Adds a big comment to `Lifetime` talking about permissable field
values.
- Adds some assertions in `new_named_lifetime` about what ident values
are permissible for the different `LifetimeRes` values.
- Adds a `Lifetime::new` constructor that does some checking to make
sure the `is_elided` and `is_anonymous` states are valid.
- `add_static_impl_trait_suggestion` now looks at `Lifetime::res`
instead of the ident when creating the suggestion. This is the one
case where `is_path_anon` doesn't replace the old empty/underscore
distinction.
- A couple of minor pretty-printing improvements.
Improve suggest construct with literal syntax instead of calling
Closing #138931
When constructing a structure through a format similar to calling a constructor, we can use verbose suggestions to hint at using literal syntax for clearer advice. The case of multiple fields is also considered here, provided that the field has the same number of arguments as CallExpr.
r? compiler
Clean up a few things in rustc_hir_analysis::check::region
Each commit is independent. They are all small clean-ups in rustc_hir_analysis::check::region.
Remove `kw::Empty` uses from `rustc_middle`.
There are several places in `rustc_middle` that check for an empty lifetime name. These checks appear to be totally unnecessary, because empty lifetime names aren't produced here. (Empty lifetime names *are* possible in `hir::Lifetime`. Perhaps there was some confusion between it and the `rustc_middle` types?)
This commit removes the `kw::Empty` checks.
r? `@lcnr`
expand: Leave traces when expanding `cfg` attributes
This is the same as https://github.com/rust-lang/rust/pull/138515, but for `cfg(true)` instead of `cfg_attr`.
The difference is that `cfg(true)`s already left "traces" after themselves - the `cfg` attributes themselves, with `expanded_inert_attrs` set to true, with full tokens, available to proc macros.
This is not a reasonably expected behavior, but it could not be removed without a replacement, because a [major rustdoc feature](https://github.com/rust-lang/rfcs/pull/3631) and a number of clippy lints rely on it. This PR implements a replacement.
This needs a crater run, because it changes observable behavior (in an intended way) - proc macros can no longer see expanded `cfg(true)` attributes.
(Some minor unnecessary special casing for `sym::cfg_attr` is also removed in this PR.)
r? `@nnethercote`
Rollup of 10 pull requests
Successful merges:
- #130883 (Add environment variable query)
- #138624 (Add mipsel maintainer)
- #138672 (Avoiding calling queries when collecting active queries)
- #138935 (Update wg-prio triagebot config)
- #138946 (Un-bury chapters from the chapter list in rustc book)
- #138964 (Implement lint against using Interner and InferCtxtLike in random compiler crates)
- #138977 (Don't deaggregate InvocationParent just to reaggregate it again)
- #138980 (Collect items referenced from var_debug_info)
- #138985 (Use the correct binder scope for elided lifetimes in assoc consts)
- #138987 (Always emit `native-static-libs` note, even if it is empty)
r? `@ghost`
`@rustbot` modify labels: rollup
Use the correct binder scope for elided lifetimes in assoc consts
Beyond diagnostics this has no real effect, and it's also just about a future incompat lint. But it causes ICEs in some refactorings that I'm doing, so trying to get it out of the way
Collect items referenced from var_debug_info
The collection is limited to full debuginfo builds to match behavior of FunctionCx::compute_per_local_var_debug_info.
Fixes#138942.
Don't deaggregate InvocationParent just to reaggregate it again
Also makes it easier to add more things to it in the future (which I am doing in some local experiments, so not really a reason to do this just now, but I think this PR stands on its own).
Implement lint against using Interner and InferCtxtLike in random compiler crates
Often `Interner` defines similar methods to `TyCtxt` (but often simplified due to the simpler API surface of the type system layer for the new solver), which people will either unintentionally or intentionally import and use. Let's discourage that.
r? lcnr
Avoiding calling queries when collecting active queries
This PR changes active query collection to no longer call queries. Instead the fields needing queries have their computation delayed to when an cycle error is emitted or when printing the query backtrace in a panic.
This is done by splitting the fields in `QueryStackFrame` needing queries into a new `QueryStackFrameExtra` type. When collecting queries `QueryStackFrame` will contain a closure that can create `QueryStackFrameExtra`, which does make use of queries. Calling `lift` on a `QueryStackFrame` or `CycleError` will convert it to a variant containing `QueryStackFrameExtra` using those closures.
This also only calls queries needed to collect information on a cycle errors, instead of information on all active queries.
Calling queries when collecting active queries is a bit odd. Calling queries should not be done in the deadlock handler at all.
This avoids the out of memory scenario in https://github.com/rust-lang/rust/issues/124901.
Add environment variable query
Generally, `rustc` prefers command-line arguments, but in some cases, an environment variable really is the most sensible option. We should make sure that this works properly with the compiler's change-tracking mechanisms, such that changing the relevant environment variable causes a rebuild.
This PR is a first step forwards in doing that.
Part of the work needed to do https://github.com/rust-lang/rust/issues/118204, see https://github.com/rust-lang/rust/pull/129342 for some discussion.
r? ``@petrochenkov``
Instantiate binder before registering nested obligations for auto/built-in traits
Instead of turning a `Binder<Vec<Ty>>` into a bunch of higher-ranked predicates, instantiate the binder eagerly *once* and turn them into a bunch of non-higher-ranked predicates.
Right now this feels like a noop, but this `enter_forall_and_leak_universe` call would be the singular place where we could instantiate bound lifetime assumptions for coroutine witnesses... if we had them. Thus consolidating the binder instantiation here is useful if we want to fix the coroutine-auto-trait problem.
r? lcnr
Remove `prev_index_to_index` field from `CurrentDepGraph`
The dep graph currently has 2 ways to map a previous index into a current index. The `prev_index_to_index` map stores the current index equivalent of a previous index. For indices which are marked green, we also store the same information in the `DepNodeColorMap`. We actually only need to known the mapping for green nodes however, so this PR removes `prev_index_to_index` and instead makes use of the `DepNodeColorMap`.
To avoid racing when promoting a node from the previous session, the encoder lock is now used to ensure only one thread encodes the promoted node. This was previously done by the lock in `prev_index_to_index`.
This also changes `nodes_newly_allocated_in_current_session` used to detect duplicate dep nodes to contain both new and previous nodes, which is simpler and can better catch duplicates.
The dep node index encoding used in `DepNodeColorMap` is tweak to avoid subtraction / addition to optimize accessing the current equivalent of a previous index.
r? `@oli-obk`
